SMELT-REDUCTION METHOD FOR TOP AND BOTTOM BLOW REFINING FURNACE

PURPOSE:To make smelt-reduction of ore with high productivity by charging coke and various oxide metal ores onto the molten slag in a top and bottom blown refining furnace, ejecting an oxygen-contg. gas from bottom blowing nozzles in the form of bubbles and ejecting oxygen from plural top blowing lances in the positions deviated therefrom. CONSTITUTION:Solid carbonaceous fuel such as coke is charged to the surface of the molten slag 7 in the top and bottom blown refining furnace 2 provided with the plural oxygen top blowing lances 4a, 4b and bottom blowing nozzles 3a, 3b and the gaseous oxygen is blown from the lances 4a, 4b to burn the coke. The oxygen-contg. gas such as air is ejected from the nozzles 3a, 3b existing in the positions deviated from right under the lances 4a, 4b to stir and heat up molten iron 5 and the molten slag 7. The metal oxide-contg. raw materials such as Fe ore, Mn ore and Cr ore charged into the furnace are simultaneously melted and the Fe2O3, MnO2, Cr2O3, etc., in the ores are reduced to Fe, Mn and Cr which are then added to and incorporated into the molten iron 5. The alloy pig subjected to the component adjustment is thus smelted with high productivity.